In this thesis, three broadband low-noise mixing circuits which use CMOS 130 nm technology are presented. As one of the first few stages in a receiving front-end, stringent requirements are posted on mixer performance. The Gilbert cell mixers have presented excellent properties and achieved wide applications. However, the noise of a conventional active Gilbert cell mixer is high. This thesis demonstrates both passive and active mixing circuits with improved noise performance while maintaining the advantages of the Gilbert cell-based mixing core. Furthermore, wide bandwidth and variable gain are implemented, making the designed mixers multi-functional, yet with compact sizes and low power consumptions.
The first circuit is a passive 2x subharmonic mixer that works from 4.5 GHz to 8.5 GHz. The subharmonic mixing core is a two-stage passive Gilbert cell driven by a quadrature LO signal. Together with a noise-cancelling transconductor and an inverter-based TIA, this subharmonic mixer possesses an excellent broadband conversion gain and a low noise figure. Measurement results show a high conversion gain of 16 dB and a low average DSB NF of 9 dB.
The second design is a broadband low-noise variable gain mixer which operates between 1 and 6 GHz. The transconductor stage is implemented with noise cancellation and current bleeding techniques. Series inductive peaking is used to extend the bandwidth. Gain variation is achieved by a current-steering IF stage. Measurements show a wide gain control range of 13 dB and a low noise performance over the entire frequency and gain range. The lowest DSB NF is 3.8 dB and the highest DSB NF is 14.2 dB.
The Third design is a broadband low-noise mixer with linear-in-dB gain control scheme. Using the same transconductance stage with the second circuit, this design also works from 1 to 6 GHz. A 10 dB linear-in-dB gain control range is achieved using an R-r load network with a linear-in-dB error less than $\pm$ 0.5 dB. Low noise performance is achieved. For different frequencies and conversion gains, the lowest DSB NF is 3.8 dB and the highest DSB NF is 12 dB. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2013-10-02 04:37:31.606
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/8398 |
| Date | 03 October 2013 |
| Creators | Jiang, FAN |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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